Combined fan and classifier



Filed Sept. 15. 1928 /Nl EN ATTORNEY Patented Dec. 23, 1930 UNITED STATES COMBINED IAIN AND CLASSIFIED.

Application filed September 18, 1928. Serial ll'o. 305,848.

This invention relates to a novel fan construction ada ted to remove the heavier particles from t e material laden air that is drawn into the fan casing.

In many industries air is employed to pick up, transport and carry off dust and fine materials, and it is frequently desirable to subject the material laden air to subsequent treatments to remove the materials therefrom.

1 In many cases the volume of air employed to pick up and carry ofi the dust and light materials is so great t at the subsequent treatment of this vast volume of air to remove the materials therefrom is a serious problem.

Fans are commonly employed to produce the air currents required to pick upand carry off the dust and light materials, and the present invention relates to a novel fan construction whereby the fan in addition to performing its naturalfunction of forcing air from one point to another serves also to separate the materials out of the air passing through the fan casing, thus making subsequent treatment of the air discharged from the fan unnecessary.

In carrying out the present invention the fan is provided with a tapered core having an outwardly flaring flange, and the construction is such that as the material laden air is drawn into the fan casing by the rotating fan the materials which are carried against the core by their momentum will be directed by the outwardly flaring flan e toward a material receiving opening, w ile the air from which these materials have been removed will be discharged through a difierent opening. The materials directed toward saidopening upon passin therethrough may enter a collecting cham er in which they are allowed to settle. I

The various features of the invention and novel combination of parts will be best understood from the followin description when read in connection with t e accompanying drawings illustrating good practical forms of the invention.

In the drawings:

Fig. 1 is a front elevation of a combined fan and classifier constructed in accordance with the present invention;

Fig. 2 is a sectional view taken on the line 2 2 of Fig. 1; and

Fi 3 is a sectional view similar to Fig. 2 but s ows a modified fan construction.

In the embodiment of the invention illustrated in the drawings the fan casing is provided with a front wall 10, a rear wall 11, and an annular wall 12 that surrounds the rotating fan and has its opposite ed es secured to the front and rear walls of t e casin as will be apparent from F1 2.

he material laden air is led to the fan throu h a pipe 13 which delivers the material aden air through a central openin in the front wall 10 into the fan casing. he blast of air which is dischar ed from the fan casing by the rotating an is forced through the air discharge pipe 14.

In accordance with the present invention,

the rotating fan extends into the fan casing through an annular opening formed in the rear wall 11 of the casing, and this fan is.provided with the fan blades 15 and with a tapered central core 16 which core may be securedto or formed integral with the fan driving shaft 17. .The shaft 17 is journalled in the bearing blocks 18 which are supported by uprights 19 that project upwardly from the fan supporting base 20 and the shaft 17 is provide with a pulley 21 which may be rotat'ed b a belt, not shown.

As a ove pointed out, the fan forming the subject-matter of the present invention serves not only to force air from one point to another but also to remove the heavier particles from the material laden air supplied to the fan.

This is accomplished in accordance with the present invention by giving the core 16 the tapered construction shown and having a pointed end 22 that ro'ects through the air mlet opening into t e eed pipe 13, and at' the rear portion of thecore 16 is provided an outwardly flaring annular flange 23 which, in the construction shown, is secured to an annular. castin 24 rigidly secured to the power shaft 17. e flange 23 is disposed in spaced relation to the annular opening formed in the rear wall 11 of the fan casing, the construction being such that when the fan is rotated the material laden air will be drawn into the pass downwardly fan casing by the suction of the fan and the heavier materials will be carried by their momentum against the core 16 and will travel along the outwardly flaring flange 23 through the discharge opening 25, as will be apparent from Fig. 2. The major portion of the air entering the fan casing and from which the heavier materials have been removed in the manner just described will be forced by the fan blades 15 outwardly through the air discharge pipe 14. If desired, the relatively fine particles that remain in the air delivered to the pipe 14 may be removed therefrom by connecting this pipe to a dust collector, not shown.

The heavier particles upon escaping from the fan casing through the material discharge opening 25 pass into a collecting receptacle 26 disposed adjacent the rear wall 11 of the casing, and this receptacle in the construction shown has an enlarged upper portion 27 in which the air which enters this receptacle may expand to promote settling of the heavier particles out of the air. These particles will into the reduced lower end portion 28 of the receptacle and through the discharge pipe 29 into the closed bin 30, or, if desired, the discharge pipe 29 may lead to a classifier or the like, not shown. Some air will necessarily enter the receptacle 26 with the materials discharged through the annular slot 25 and this air may be discharged through a conduit 31 which, in the construction shown, serves to return this air to the pipe 14. The volume of air which is permitted to pass through the conduit 31 may be controlled by the sliding gate 32.

It will be apparent that the shape of the outwardly flaring annular flange 23 may be varied within a relatively wide range, so long as it serves to gradually deflect the materials outwardly through the material discharge passage 25, and it will be noted in the construction shown in Fig. 2 that the flange plate 23 is given the shape of a flattened cone, whereas, in the modified construction of Fig. 3 the annular flange 33 gradually curves outwardly into a plane disposed at right angles to the power shaft 17.

It will be apparent from the foregoing that the rotation of the fan above described will serve to draw the material laden air into the fan casing through the inlet pipe 13. The speed at which this air enters the casing will cause the heavier particles within the air to be carried by their momentum against the tapered core so that they will be directed outwardly by this core and the annular flange 23 through the material discharge opening 25 into the collecting receptacle 26, and that the air from which the heavier particles are removed will be forced outwardly by the fan blades 15 through the air discharge pipe 14. It will therefore be seen that the combined fan and classifier forming the subject-matter of the present invention constitutes an extremely simple and satisfactory construction for removing the heavier particles from the material laden air supplied to the fan.

lVhat is claimed is:

1. A combined fan and classifier comprising in combination, a fan casing having an air inlet opening formed in its front wall to receive material laden air and having a material discharge opening adjacent its rear wall and an air discharge opening, a fan supported to rotate within the casing and provided with fan blades and a tapered core having an outwardly flaring annular flange that extends rearwardly through said rear Wall and c011- structed so that the heavier particles sucked into the casing with the air will strike against the outwardly flaring flange and travel along the same toward the material discharge opening while the air from which the heavier ma terials are removed is forced by the fan through said air discharge opening, and a collecting receptacle communicating with the fan casing to receive the heavier materials discharged from the fan casing.

2. A combined fan and classifier comprising in combination, a fan casing having an air discharge opening, and an inlet opening in its front wall adapted to receive material laden air, a collecting receptacle adjacent its rear Wall and an opening in said rear wall for the passage of the materials from the fan casing into the collecting receptacle, and a fan supported to rotate within the casing and provided with fan blades and a tapered outwardly and rearwardly flaring flange constructed to direct the heavier particles in the air through the opening in said rear wall into said receptacle.

3. A combined fan and classifier comprising in combination, a fan casing having an air discharge opening, an inlet opening in its front Wall adapted to receive material laden air, and a fan receiving opening in its rear wall, a collecting receptacle surrounding said fan receiving opening, and a fan mounted to rotate in the fan casing and provided with fan blades and a core having an outwardly flaring flange adapted to direct the heavier materials through the fan receiving opening in said rear wall into said receptacle.

4. A combined fan and classifier comprising in combination, a fan casing having an air discharge opening through which the major portion of the air from the fan is discharged, an inlet opening in its front wall adapted to receive material laden air and a material discharge opening in its rear wall and within which the rear portion of the fan rotates, a collecting receptacle for receiving the materials discharged through said rear opening, a fan mounted to rotate in the easing and provided with fan blades and an outwardly flaring flange adapted to direct the materials that enter the fan casing outrestricted annular opening into said recepwardly through said material discharge tacle.

opening. In testimony whereof, I have signed my 5. A combined fan and classifier comprisname to this specification. 5 ing in combinatiomafan casing having an in- ALBERT H. STEBBINS. 70

let opening in its front wall to receive material laden air and having a material discharge opening adjacent its rear wall, a discharge pipe for conducting air from the casing, a collecting receptacle disposed adjacent said rear wall, a fan mounted to rotate in the fan casing and provided with fan blades and an outwardly flaring flange for directing the materials outwardly through the material discharge opening of saidrear wall into the collecting receptacle, and a conduit for conducting air from said collecting receptacle to said discharge pipe.

6. A combined fan and classifier comprising in combination, a fan casing having an inlet opening formed in the front wall of the casin to receive material laden air, a fan rotatably mounted in said casing, an air outlet opening, and a material discharge opening formed in the rear wall of the casing to surround the rotating fan, a receptacle adjacent the rear wall of the fan casing to receive the materials discharged throu 11 said 0 ening, said fan being provided with fan bla es and with an annular outwardly flaring flange constructed to direct the materials that enter the fan casing through said material discharge opening while the air from which the materialsare removed is forced by the fan blades through said air outlet. 1

7. A combined fan and classifier comprising in combination, a fan casing having an inlet opening formed in the front wall of the casing to receive material laden air and an air 40 outlet opening, a fan rotatabl mountedin I said casing and provided with an blades and with an annular o"twardly flaring flange positioned to rotate within a surrounding wall of the casing and sufficiently close thereto to form an annular material discharge slot beno tween said wall and flange, and means to rotate the fan to cause the fan blades to force the air from which the materials are removed through the air discharge opening while the materials are directed by the flange through 115 said annular slot.

8. A combined fan and classifier comprising in combination, a fan casing having a front and rear wall, and provided with an air discharge opening and an inlet opening in its front wall adapted to receive material laden air, a collecting receptacle provided with a restricted annular opening adjacent said rear wall and leading from the fan cas- 13 ing into the receptacle, and a fan mounted to rotate in the fan casing and provided with fan blades and a core having an outwardly flaring flange adapted to direct the heavier materials in the air outwardly through said I 130 

